Acute myocarditis and pulmonary edema due to

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Acute myocarditis and pulmonary edema due to scorpion sting Cardiology & Cardiac Surgery Department, Hamad Medical Corporation, Doha, Qatar *Email: [email protected]

Montaser Ismail, Nidal Asaad*, Jassim Al Suwaidi, Maryam Al Kawari, Amar Salam ABSTRACT Objective: To present a case of a serious manifestation of scorpion sting, which was not reported before in Qatar, review the literature, and compare with previously reported similar cases. Case presentation and intervention: A young male patient was admitted to CCU with a clinical picture of acute toxic myocarditis and cardiogenic shock with abnormal ECG and elevated cardiac markers after a scorpion sting to his right big toe. Thorough investigations, including echocardiography, cardiac MRI and right heart catheterization, supported the diagnosis. Coronary angiography was normal. Patient was managed conservatively with supportive measures, mechanical ventilation, IV fluids, inotropic agents, steroids, antibiotics and Prazocin. Over 9 days of hospital course, patient gradually improved, was successfully extubated, and was discharged in a stable condition. Conclusion: Toxic myocarditis (with myocardial damage), pulmonary edema and cardiogenic shock are reported manifestations of scorpion venom intoxication. Keywords: scorpion sting, myocarditis, cardiogenic shock

http://dx.doi.org/ 10.21542/gcsp.2016.10 Submitted: 1 July 2015 Accepted: 8 April 2016 c 2016 The Author(s), licensee Magdi Yacoub Institute. This is an open access article distributed under the terms of the Creative Commons Attribution license CC BY-4.0, which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited.

Cite this article as: Ismail M, Asaad N, Al Suwaidi J, Al Kawari M, Salam A. Acute myocarditis and pulmonary edema due to scorpion sting, Global Cardiology Science and Practice 2016:10 http://dx.doi.org/10.21542/gcsp.2016.10

Page 2 of 10 Ismail et al. GCSP 2016:10

INTRODUCTION Creatures that are capable of producing a poison in a gland and then delivering that toxin by stinging or biting are called venomous animals. Arthropods (scorpions, spiders, bees, and wasps) are examples. Scorpion envenomation is potentially fatal in many regions worldwide. Children form the majority of victims. The sting effect depends on the size of the victim, the season, the age of the offender and the delivery dose of the scorpion1,3 . Several clinical syndromes with variable hemodynamic patterns may dominate the clinical presentation2,3 . There have been many case reports and reviews about scorpion sting-related myocardial dysfunction and hemodynamic disturbances, mainly in the endemic areas. The Middle East has a relatively high incidence of scorpion envenomation; however no similar cases were reported in Qatar previously. Leiurus Quinquestriatus (Figure 1), and Androctonus crassicauda are the most common scorpion offenders in the Gulf Area and Saudi Arabia1 (Table 1). Here we present a case of myocardial damage and cardiogenic shock as a result of a scorpion envenomation.

CASE REPORT A 24-year-old Nepalese male patient who worked as a shepherd in a suburban farm in Doha, Qatar, and with no significant past medical history, presented to the emergency room with a sudden onset of nausea, vomitting, dizziness and profuse sweating around 30 minutes after a scorpion sting to the right big toe. The patient described the scorpion as ‘‘yellowish-white color’’. Upon arrival to the emergency room, the patient was still having severe pain localized at the site of sting. A physical examination revealed a young male patient who was conscious, oriented but anxious. He looked sick, sweaty, pale and dyspnic. He was hypotensive with a blood pressure of 75 mmHg systolic and 55 mmHg diastolic, and tachycardiac with regular heart beats of 125 beat per minute. He had raised jugular venous pressure, bilateral diffuse lung fields crepitations up to the mid-zones, normal first and second heart sounds and summation gallop. No focal neurological deficits. By this time patient had received the scorpion anti-venom (1 vial intravenous), IV hydrocortisone 200 mg, and 2000 ml of normal saline over 4 hrs. The IV fluids were stopped when the patient developed signs of pulmonary edema. ECG showed sinus tachycardia with diffuse ST segment depression (Figure 2). Cardiac markers came positive (Troponin T: 0.26–1.3 ng/ml, CK-MB: 52 ng/ml) and pro BNP was elevated (4216 pg/ml). Chest radiography showed moderately severe lung congestion (Figure 3). Urgent echocardiography revealed moderate to severe left ventricular global hypokinesia and impaired systolic function (ejection fraction of 35%) with mild mitral regurgitation and normal study otherwise. Patient was admitted to CCU with an admission diagnosis of toxic myocarditis and cardiogenic shock. The patient was intubated, mechanically ventilated and maintained on titratable doses of both inotropic agents noradrenaline and dopamine, and maintenance doses of IV hydrocortisone and antibiotics (piperacillin plus tazobactam). Right heart catheterization suggested a picture of cardiogenic shock with cardiac output of 1.88 l/min (normal: 4.5–7 l/min), cardiac index of 1.34 l/min/m2 (normal: 2.5–4.2 l/min/m2 ), systemic vascular resistence of 3150 d s/cm5 (normal: 800–1200 d s/cm5 ), and pulmonary capillary wedge pressure of 32 mmHg (normal: 6–12 mmHg) (Figure 4). Next day, the patient was febrile with a temprature of 39 C. He developed short runs of ventricular tachycardia (Figure 5) which spontaneously resolved. Two days after admission,


Figure 1. Leiurus Quinquestriatus: one of the comon scorpion species in the Middle East and Saudi Arabia.

Table 1. Major scorpion offenders. USA: Centroides exilicauda Brazil, S. America: Tityus serrulatus Mexico: Centroides sufusus India: Buthus tamulus Spain: Buthus occitanus Saudia Arabia: Leiurus quinquestriatus, Androctonus crassicauda Middle East: Leiurus quinquestriatus, Buthus minax, Androctonus N. africa: Androctonus australis, Buthus occitanus, Leuirus S. Africa: Androctonus crassicauda Persian Gulf: Androctonus crassicauda

his ECG showed sinus rhythm with resolution of the ST segment changes and prolongation of QT interval, corrected QT interval was 503 ms (Figure 6a), while the QT interval was partially normalized five days after admission with a corrected QT interval of 471 ms (Figure 6b). Prazocin (1mg orally twice daily) was then started after hemodynamic stabilization and withdrawal of inotropic agents. Cardiac MRI with gadolinium contrast was arranged, and revealed global LV hypokinesia and systolic dysfunction with global myocardial edema suggestive of diffuse myocarditis; no evidence of myocardial scar by delayed gadolinum enhancement views (Figures 7 and 8). After one week of CCU course, patient was off-sedation, fully conscious, afebrile wih stable hemodynamics. He was maintaining good oxygen saturation on 40% FiO2 , with clear lung fields. He was then successfully extubated. Two days later, echocardiography revealed significant improvement with normal LV systolic function (EF: 55%). Coronary angiography was normal for both left and right coronary arteries (Figures 9 and 10). Patient was discharged home in a stable condition, on proton pump inhibitor (Rabiprazole 20mg once/day) and a plan for outpatient follow up.


Figure 2. Electrocardiography (ECG) revealing sinus tachycardia with diffuse repolarization abnormalities.

Figure 3. Chest x-ray showing moderate to severe pulmonary edema with borderline heart size.

DISCUSSION Clinical manifestation of scorpion envenomation varies from a localized pain in the site of the sting to a severe generalized intoxication. Cardiovascular involvement include hemodynamic disturbances with hypertensive phase and tachycardia dominating the majority of cases (including Leiurus Quinquestriatus envenomation), this can be associated with hypertensive encephalopathy. Occasionally hypotension with or without bradycardia is the dominating hemodynamic picture1,2 . In a review of hemodynamic patterns in eight patients in India, vascular constriction with marked hypertention was prominent in one case, thought to have mild envenomation.


Figure 4. Hemodynamic parameters suggestive of cardiogenic shock.

Figure 5. ECG monitor tracing showing short run of polymorphic V-Tac.

In the other seven cases, with potentially more severe envenomation, the LV systolic dysfunction with pulmonary edema was the dominating picture with marked tachycardia and variable degrees of hypotention, preceded in some cases by a brief hypertensive phase. One fatal cardiogenic shock was reported2 . Pulmonary edema in another review ranged from 7% to 46%, with cardiogenic shock observed in a large number of these cases. Cardiogenic shock usually follows, and occasionally precedes, the hypertensive phase. Cardiac arrest was observed in around 7% of cases3 . Sinus tachycardia, variable ST-T changes and prolonged QTc are the most common ECG changes reported in scorpion envenomation. Other changes include bradycardia,


6-A

6-B

Figure 6. (A) ECG 2 days after admission, revealing sinus tachycardia with resolution of the initial ST-T changes and a prolonged Q-T interval. Corrected Q-T (QTc = 503 ms). (B) Repeated ECG 5 days after admission showing partial normalization of Q-T interval (QTc = 471 ms).

myocardial infarction-like changes, conduction abnormalities and rhythm disturbances1 . Life-threatening ventricular arrhythmias were reported as well4 . Laboratory findings include elevated cardiac markers (CK, CK-MB, Troponin, SGOT), and elevated plasma and urine chatecolamines. In one review of 32 children following Leiurus Quinquestriatus envenomation, 13 out of 32 patients (40.6%) had evidence of myocardial damage manifested by elevated cardiac enzymes (CK, CK-MB, SGOT) and CK-MB/CK ratio > 6%, while only 6 out of these 13 patients had ECG changes suggestive of myocardial injury5 . Both echocardiography and nuclear scintigraphy show global hypokinesia with LV systolic and diastolic dysfunction in the majority of cases, most of which were found to improve gradually till complete resolution1 . In a 16 patient review in Venzuella, this echocardiographic finding of diffuse hypokinesia was associated with higher plasma


7-A

7-B

Figure 7. Cardiac MRI showing global LV hypokinesia. 7a: 2-chamber view end-diastolic, 7b: 2-chamber view end-systolic.

Figure 8. Cardiac MRI (Dark Blood T2WI) shows diffuse high signal intensity within the myocardium (arrow) representing a diffuse myocardial edema (acute myocarditis).

levels of noradrenaline. With gradual clinical improvement, both noradrenaline levels and LV contractility with systolic function were normalized simultaneously6 . A cohort study of nine patients with scorpion (Androctonus australis) envenomation in Tunisia found a correlation between the depressed LV systolic function, which was reported in all 9 patients (EF: 26 +/ 12%), and the hemodynamic profile which was in all patients suggestive of acute congestive heart failure (PCWP: 24 +/ 2 mmHg). Other echocardiographic findings


Figure 9. Left coronary artery angiography shows normal vessels.

Figure 10. Right coronary artery angiography showing normal study.

included transient mitral regurgitation and LV diastolic function. One mortality case was reported, otherwise the other 8 patients improved gradually over 5-7 days untill complete recovery7 . In our case, which is the first to reported in Qatar, the initial presentation was hypotention, tachycardia and heart failure. However there were a few hours prior to the patient’s presentation during which his hemodynamic picture was unknown. The invasive hemodynamic study completed immediately after admission confirmed the cardiogenic rather than anaphylactic or septic etiology of his shock status. Laboratory,


Table 2. Summary of remarkable reviews, their countries, number of patients, purpose of review, and results.

Karnad DR

Country

No of Pts

Purpose

Results

India

8

Hemodynamic profiles

1 hypertensive/tachycardia 7 hypotensive/pulmonary edema/cardiogenic shock 1 mortality

Sofer S, et al.

Israel

32 (children)

Myocardial injury

13 pt (40%) myocardial damage (high enzymes) 6 pt (18-20%) ECG abnormalities

Mazzei de Dàvila CA, et al.

Venzuella

16 (with LV dysfuction)

Relation between LV dysfunction & Sympathetic activity

All cases with some degree of LV dysfunction have high levels of NE.

Abroug F, et al.

Tunisia

9 (with CHF)

Presentation & Outcomes

All with LV dysfunction (EF: 26 ± 12 %)

All with CHF (PCWP: 24 ± 2 mmHg).

8 improved/full recovery 1 mortality Ismail M, et al.

Saudi Arabia

3800 (all scorpion sting cases)

Antivenome administration & Outcome

The earlier the Anti-venome given the better the outcome. Nigligible CVS manifestations

Bawaskar HS, et al.

West india

658

Prazocin & Outcome

>20% mortality in pre-Prazocin era